[Available] Xerneas

General:While Kyogre has been ruling Ubers for the past 2 generations, Generation 6 brings a complete and dominant threat. Xerneas, even by Ubers standards, is one of the best sweepers in the game. With a great ability and its signature move Geomancy, it hits nearly everything for massive damage after only using one turn of setup with the item Power Herb. Like with Kyogre in the previous generations, one must have a solid check to this monster on every team.

This is Xerneas' most dominant set. With Power Herb, Xerneas can bypass the two-turn setup that Geomancy requires and gain +2 in Special Attack, Special Defense, and Speed in only one turn. Moonblast is used for a strong STAB that is boosted further by Fairy Aura. Focus Blast is used to hit the Steel types that Moonblast cannot. Hidden Power Fire can be used as an alternative to hit Aegislash and Scizor. Psyshock can be used for Xerneas to power through Special Walls such as Chansey, and Arceus-Poison. Thunder can be used alternatively to hit tanks such as Ho-Oh. The EV spread is used to provide maximum power for Xerneas' attacks as well as allow it to outspeed the unboosted metagame. To every great threat, there is a weakness though. If switched/phazed back out after using Geomancy once, Xerneas is almost useless for the rest of the game. The key is playing smart.

Another role that Xerneas can take on is revenge killer. With good off-the-bat power from Moonblast (boosted by STAB and Fairy Aura), and three coverage moves to cover its weaknesses, Xerneas can serve as an effective revenge killer in the metagame. Although more easily stopped than the Geomancy set, Choice Scarf Xerneas does not have to worry about being useless after being switched out just once.

One interesting set that Xerneas can take on is the Mixed set. This set is designed to bait in certain threats and remove them. Naive Nature along with 224 Speed EVs allow Xerneas to outspeed Base 95 Speed Pokemon. The attack EVs ensures that Rock Slide will be a OHKO on Max HP Ho-Oh. Moonblast is for a reliable STAB move that is powered up by Fairy Aura. Close Combat is used to nail the common Chansey/Blissey that like to switch in on Xerneas. Life Orb can be used as an alternative to Expert Belt, but it can be less effective as it takes away the surprise factor of not having Power Herb.Other Options:Although the three sets outlined above are really what makes Xerneas so dominant in the Ubers metagame, Xerneas can perform a variety of roles. On Stall teams, Xerneas can run a cleric set with Aromatherapy with Rest, Sleep Talk, and Moonblast (for reliable damage output). With great moves like Close Combat, Rock Slide, and Megahorn, that utilize Xerneas' Attack stat, it can run a pure Attacking set, although, it does lack a physical Fairy STAB move. Geomancy + Power Herb along with Substitute and Moonblast plus Thunder / Psyshock / Focus Blast can be a viable option to set up Substitute on Chansey/Blissey/Clefable.

Checks and Counters:Because Xerneas is so versatile and threatening, it is very hard to counter. However, there are ways to do it. With Specially Defensive Clefable and its Unaware ability, it can effectively stall out Xerneas at +2. Specially Defensive Steel-type Pokemon such as Bronzong, Jirachi, Klefki and Heatran can also be used as solid checks to Xerneas, barring Hidden Power Fire for the first three and Focus Blast for Heatran. Chansey, who has always been known as a Specially Defensive beast, can take a few hits. However, Focus Blast or Psyshock will eventually wear it down. A Choice Band Scizor may also be used to check Xerneas with its super-effective Bullet Punch. Amoonguss can put a stop to variants lacking Psyshock. Choice Scarf Imposter Ditto can come in and revenge kill a boosted Xerneas and immediately pose as a threat to the rest of the team.

Please give thoughts on this and how it can be improved (including grammar). Thanks!

Horribly short.Needs more sets like cleric(aromatherapy resttalk and stuff) and maybe calm mind in as it can be used more than once and hurts with life orb.Life Orb mixed is also viable. Will suggest more later when I get time.

Thunderbolt is inferior to thunder as u miss out on the 2hko of the steel/psychics with hazards/a little residual damage
Hp fire is pretty much only useful against scizor who can otherwise 2hko u before u can 2hko back thanks to priority so definitely mention him if u wanna include hp fire
Hp rock really doesn't deserve a mention since thunder/psyshock both ohko after rocks anyway

Definitely deserves it's own set especially as a cool lure
E belt
Moon blast/close combat/rock slide/aromatherapy
Not sure what other people use but I run 196 Atk/ 88 spa/ 224 spe naive
Lets u outspeed base 95s, always ohkos 252 hp ho oh and rest in spa
Some people like life orb, but then u can't feign geo herb
If u wanna mention lo run 224 speed enough Atk to ohko ho oh and rest in spa

Haven't tried out the rest talk set

Other options

Remove physical xern (and mix xern since it has it's own set)
If u wanna keep it mention it is not very effective because it lacks a physical fairy stab

Sets stuff:
Specially Defensive and mixed LO definitely deserve their own sets so add those please. I'm not exactly sure on CM since Fairyceus is almost always a better option for that job with reliable recovery, more bulk and speed. It belongs in OO imo. Specially Defensive Xern is a formidable wall which will always beat big threats such as Palkia, Yveltal and more. Mixed (without LO it's a very cool lure but it kinda lacks power when using Moonblast then) is a very cool set as well. Moveset probably looks like this Moonblast / Rock Slide / Close Combat or Focus Blast / Night Slash to wear down Aegi, but Aromatherapy, Grass Knot, Thunder etc all work.

Nitpicks:
As far as other things go, Thunderbolt is a bad move on Xerneas considering a regular Moonblast does more damage than a super effective Thunderbolt. Thunder (or eventually HP Rock even though I don't really like it) should always be used instead of it.
I personally never used HP Rock because I think Psyshock or Thunder are good enough to beat Ho-Oh, so yeah reconsider that maybe.
Substitute deserves a big mention somewhere since it's a nightmare to face for some teams. E.g. you laugh at Clefable with it among a lot of other things.

C&C:
Expand Aegislash to "specially defensive steel types" since Bronzong, Jirachi, SpDef Mega Zor, Heatran and Klefki all do a pretty good job at beating it, only fearing a handful of moves. Lugia and SpDef Kyogre can usually phase it out once which is enough to stop the Geomancy sets. Mention Ditto as a dangerous check as it turns the tables on you very fast, but it requires prior damage.
EDIT: ALSO WHIRLWIND/CB HO-OH WITH SOME PRIOR DAMAGE ON XERN.

Team options:
Some analyses have these so I guess it's a standard thing now? There's really only two big ones for Xern so it's not too big a deal. Mega Gengar helps a ton trapping a lot of its checks and counters such as Zong, Lugia etc. The other big one is SR since it gives Ho-Oh Lugia a hard time as well as wearing down softer checks/counters such as Heatran and Kyogre.

I think the scarf set can be improved. You don't really need Timid because you already outspeed Deoxys-A and you beat Zekrom anyway. The power difference isn't huge, but it helps on things like 2HKOs on Arceus forms and OHKOs on AV Palkia. I also don't really understand your coverage moves. If you want to hit Ho-oh then Rock Slide is the best option for doing that. Thunderbolt is meant to hit what, Volcanion????? HP Fire is probably good because it hits Scizor really hard, and the other options don't really do much to the usual switchins. There is also the option of Moonblast/Sleep Talk/no move/no move which is one of the best Darkrai counters and stays useful even after being put to sleep.

Other minor stuff:

Mention HP Rock with Geomancy either on the set or in Other Options.
How is the physical stuff you mention in Other Options different from the mixed set?
Add Aegislash to steel types in counters.
Those steels don't care about HP Fire too much, it deals the same as Focus Blast.
Chansey with 252 Def (which it should run) is only very rarely 2HKOd by Psyshock so it should win. Also doesn't mind Focus Blast unless its SDef gets lowered.
Why specifically mention choice band on Scizor? It's probably Scizor's worst set and Bullet Punch does nice damage to Xerneas from any Scizor.
In checks and counters maybe mention how hitting it as it sets up + priority from Scizor/Lucario/Ekiller is usually enough for offensive teams.

There's only one niche of the Sleep talk / MoonBlast set which is being a check to Dakrai, and I doubt it's good vs anything else compared to other sets, so I doubt it deserves a mention with such a small niche.

I'm way too busy, and Xerneas is a really important mon in the metagame and I need someone who can devote more time into writing a good analysis. So, Shadow Sneak (the first one who replied when I asked the QC) is taking over Xerneas.